package demo2;

public class Computer {
    public void poweron(){
        System.out.println("打开电脑");
    }
    public void poweroff(){
        System.out.println("关闭电脑");
    }
    public void usbService(USB usb){
        usb.openDevice();
        if(usb instanceof Mouse){
//            Mouse mouse = (Mouse) usb;
//            mouse.click();
            ((Mouse) usb).click();
        } else if (usb instanceof KeyBoard) {
            ((KeyBoard) usb).input();
        }
        usb.closeDevice();
    }
}
